Optical alignment module utilizing transparent reticle to facilitate tool calibration during high temperature process
An apparatus and method for aligning one or more components while attaching the component to a substrate. The component is positioned over the substrate. An alignment tool is attachable to the component. The alignment tool includes a tool alignment element, an optical tool, and a substrate alignment element attached to the substrate. The tool alignment element being alignable with the substrate alignment element such that the components are positioned at specified locations on the substrate for attachment to the substrate. Further, in the method according to the disclosure, the tool alignment element aligning with the substrate alignment element to position one or more components at a specified location on the substrate.
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The present invention relates to an alignment apparatus for facilitating tool calibration, and more specifically, the present invention relates to an alignment apparatus for facilitating tool calibration during high temperature processes.
Current alignment tools, for example, an alignment (or rework) tool used in a ball grid array (BGA) rework, may use an optical alignment of a component or module to a substrate. The substrate may be large substrates, for example, 35 inches×20 inches, or smaller. A typical placement accuracy for placement of a component on a substrate for current tools is about 25 microns. Heretofore, efforts to achieve greater accuracy in placement of a component on a substrate has been unsuccessful.
In one example, during semiconductor processing at high temperatures, in a solder reflow cycle, the temperature of the substrate may be greater than 200 degrees C. The reflow cycle causes solder balls attaching the component to the substrate to liquefy resulting in placement alignment being shifted. Thus, another problem with current alignment tools is that the placement of the component(s) may not be maintained. Further, certain applications need greater accuracy in placement alignment, and the alignment must also be maintained during high temperature processing. Current alignment/calibration procedures, which may be prescribed by the tool manufacturer, uses a calibration target which the tool uses to automatically calibrate the placement points for the entire working area. However, fine or slight alignment of components using the procedure falls short of desired specifications.
There is therefore a need for an improved alignment/calibration tool and method for achieving specified component alignment. It is further desirable for the alignment tool and method to provide the specified component alignment during a high temperature process. Additionally, there is need for the alignment tool and method to provide the specified component alignment during a high temperature process and maintaining the alignment of the component during a reflow cycle.
BRIEF SUMMARYIn an aspect of the present invention, an apparatus for aligning a component for attaching the component to a substrate comprises an alignment tool attachable to at least one component for attaching to a substrate. A tool alignment element is part of the tool, and a substrate alignment element is attachable to a substrate positioned beneath the alignment tool. The tool alignment element aligns with the substrate alignment element such that the component is positioned at a specified location on the substrate for attachment to the substrate.
In a related aspect, the apparatus further comprises a plurality of connection elements on the component, and a plurality of conductive pads on the substrate for mating with the connection elements on the component in mating relation when the component is positioned at the specified location. The component may be attached to the substrate using solder forming a solder ball. In a related aspect, the solder ball aligns with the substrate pad by greater than one quarter of a diameter of the solder ball connecting to the substrate pad. In another related aspect, the position of the component is maintained during a solder reflow cycle. The alignment tool may be attachable to two components, and the tool alignment element aligns with the substrate alignment element such that the components are positioned at specified locations on the substrate for attachment to the substrate. The apparatus may further include an optical tool being part of the alignment tool and the tool alignment element being transparent, wherein the optical tool aligns the tool alignment element and the substrate alignment element along an optical axis. The optical tool may align the tool alignment element and the substrate alignment element using a reticle on the substrate alignment element.
In another aspect of the invention, a method for aligning a component for attachment to a substrate comprises: attaching an alignment tool to at least one component; positioning the component on a substrate; aligning the component on the substrate using a tool alignment element being part of the alignment tool and a substrate alignment element attachable to the substrate; and aligning the component on the substrate such that the component is positioned at a specified location on the substrate for attachment to the substrate.
In a related aspect, the method further comprises: mating a plurality of connection elements on the component with a plurality of pads on the substrate when the component is positioned at the specified location. The method may further comprise forming a solder ball for attaching the component to the substrate. In a related aspect, the method further comprises: aligning the solder ball with the substrate pad for connecting the solder ball to the substrate pad, the solder ball being on the substrate pad by greater than one quarter of a diameter of the solder ball. The method may further comprise maintaining the positioning of the component on the substrate during a solder reflow cycle. The method may further comprise: attaching the alignment tool to two components; and aligning the tool alignment element with the substrate alignment element such that the components are positioned at specified locations on the substrate for attachment to the substrate.
In another aspect of the invention, an alignment system for aligning and attaching a component to a substrate comprises an alignment tool attachable to two components for attaching to a substrate, wherein each of the components includes a plurality of connection elements. A tool alignment element is part of the tool, and a substrate alignment element is attachable to a substrate positioned beneath the alignment tool. The tool alignment element aligns with the substrate alignment element such that the components are positioned at specified locations on the substrate for attachment to the substrate. A plurality of conductive pads on the substrate are for mating with the connection elements on the components in mating relation when the components are positioned at their respective specified locations.
In a related aspect, the components are attached to the substrate using solder forming a solder ball. The solder ball may align with the substrate pad by greater than one quarter of a diameter of the solder ball connecting to the substrate pad. The positions of the components may be maintained during a solder reflow cycle. The system may further include an optical tool being part of the alignment tool and the tool alignment element being transparent, wherein the optical tool aligns the tool alignment element and the substrate alignment element along an optical axis. The optical tool may align the tool alignment element and the substrate alignment element using a reticle on the substrate alignment element.
These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings, in which:
Referring to
The components 40 include a plurality of connection elements embodied as solder balls 44. The solder balls 44 align with the conductive pads embodied as solder pads 48 on the substrate 50 for mating with the solder balls 44 as shown in
The optical tool 60 of the alignment tool 10 can use lines, cross-patterns, circles, reticle 32 (
In operation, referring to
More specifically, for example, during a high temperature solder reflow process, the solder balls 44 are aligned with the solder pads 48 on the substrate 50 for mating with the solder balls 44 as shown in
Referring to
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that changes in forms and details may be made without departing from the spirit and scope of the present application. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated herein, but falls within the scope of the appended claims.
Claims
1. An apparatus for aligning a component for attaching the component to a substrate, comprising:
- an alignment tool attachable to at least one component for attaching to a substrate;
- a tool alignment element being part of the tool; and
- a substrate alignment element attachable to a substrate positioned beneath the alignment tool, the tool alignment element being alignable with the substrate alignment element such that the component is positioned at a specified location on the substrate for attachment to the substrate; and
- an optical tool being part of the alignment tool and the tool alignment element being transparent, the optical tool aligning the tool alignment element and the substrate alignment element along an optical axis.
2. The apparatus of claim 1, further comprising:
- a plurality of connection elements on the component; and
- a plurality of conductive pads on the substrate being matable with the connection elements on the component in mating relation when the component is positioned at the specified location.
3. The apparatus of claim 2, wherein the component is attachable to the substrate using solder forming a solder ball.
4. The apparatus of claim 3, wherein the solder ball is alignable with the substrate pad by greater than one quarter of a diameter of the solder ball connecting to the substrate pad.
5. The apparatus of claim 4, wherein the position of the component is maintainable during a solder reflow cycle.
6. The apparatus of claim 1, wherein the alignment tool is attachable to two components, and the tool alignment element being alignable with the substrate alignment element such that the components are positioned at specified locations on the substrate for attachment to the substrate.
7. The apparatus of claim 1, wherein the optical tool aligns the tool alignment element and the substrate alignment element using a reticle on the substrate alignment element.
8. A alignment system for aligning and attaching a component to a substrate, comprising:
- an alignment tool attachable to two components for attaching to a substrate, each of the components including a plurality of connection elements;
- a tool alignment element being part of the tool;
- a substrate alignment element attachable to a substrate positioned beneath the alignment tool, the tool alignment element being alignable with the substrate alignment element such that the components are positioned at specified locations on the substrate for attachment to the substrate; and
- a plurality of conductive pads on the substrate for mating with the connection elements on the components in mating relation when the components are positioned at their respective specified locations; and
- an optical tool being part of the alignment tool and the tool alignment element being transparent, the optical tool aligning the tool alignment element and the substrate alignment element along an optical axis.
9. The system of claim 8, wherein the components are attachable to the substrate using solder forming a solder ball.
10. The system of claim 8, wherein the solder ball are alignable with the substrate pad by greater than one quarter of a diameter of the solder ball connecting to the substrate pad.
11. The system of claim 10, wherein the positions of the components are maintainable during a solder reflow cycle.
12. The system of claim 8, wherein the optical tool is alignable the tool alignment element and the substrate alignment element using a reticle on the substrate alignment element.
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Type: Grant
Filed: Nov 23, 2009
Date of Patent: May 15, 2012
Patent Publication Number: 20110119909
Assignee: International Business Machines Corporation (Armonk, NY)
Inventors: Fuad E. Doany (Yorktown Heights, NY), Andrew D. Perez (Yorktown Heights, NY), Niranjana Ruiz (Somers, NY), Lavanya Turlapati (Yorktown Heights, NY)
Primary Examiner: Minh Trinh
Attorney: Scully, Scott, Murphy & Presser, P.C.
Application Number: 12/623,836
International Classification: B23P 19/00 (20060101);